Kerry is a dolt and has always been a dolt. His answer makes no sense if you look at it in total. No sense whatsoever, but then, I expect no better from him.
Shieffer's comment, on the other hand, is inexcusable. As a journalist, he was bound by ethics to remain neutral but did not. If he meant it as "yeah, and so?," his timing was horrible. Worse, to pretend that answer made sense is ridiculous. I bet if you asked Shieffer to dissect what Kerry had just said, he would not have been able to.
I used to point similar out about Kerry's campaign speeches. On close exam, many of his statements made little or no sense at all. They were (and continue to be) rambling, incoherent, disconnected words put together. He has actually contradicted himself in the same speech, and sometimes in the same paragraph or sentence.